• 제목/요약/키워드: Figure of Merit

검색결과 436건 처리시간 0.026초

토지 이용 변화 예측 모형의 정확도 검정을 위한 통계량 연구 (Assessing the Metric to Measuring Land-Use Change Suitability)

  • 김오석
    • 한국경제지리학회지
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    • 제16권3호
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    • pp.458-471
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    • 2013
  • 본 논문은 토지 이용 변화를 예측하는 계량 모형의 정확도 평가에 필수적인 통계량인 성능 지수를 심도 있게 이해하는 것을 목적으로 한다. 이 통계량은 기존의 토지 이용 변화 연구에서 소개된 예측 모형의 정확도를 평가하는 다른 통계량들 (예: 카파 통계량)의 단점을 보완하여 만들어진 것이나, 이 또한 계량 모형의 예측력을 명확하게 평가하고 해석하기에는 제한적이다. 본 논문에서는 성능 지수의 보다 명확한 해석을 위해서 결과물의 공간해상도를 고정해야 함을 밝히고, 그 특정 공간해상도를 "성능 해상도"라 정의한다. 성능 해상도는 예측오류가 현격하게 줄어들면서 계량모형의 예측력이 증가하는 시점의 공간해상도를 일컫는다. 따라서 토지 이용 변화 예측 모형의 예측력을 정확하게 평가하기 위해 두 통계량, 즉 성능 지수와 성능 해상도를 함께 이용할 것을 제안한다.

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Hall소자 재료의 특성지수 (The figure of merit for hall element materials)

  • 이정한
    • 전기의세계
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    • 제25권4호
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    • pp.53-58
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    • 1976
  • Criteria and significance of the factor .root..mu..$R_{u}$ or ($R_{u}$/.root.p) in Hall element material selection are discussed. And the chart which is useful to compare the figure of merit F=.root..mu..$R_{u}$ in Hall element materials is presented with the F's for some practical Hall device materials.als.

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Analysis of Pull-in-Voltage and Figure-of-Merit of Capacitive MEMS Switch

  • Saha, Rajesh;Maity, Santanu;Devi, Ngasepam Monica;Bhunia, Chandan Tilak
    • Transactions on Electrical and Electronic Materials
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    • 제17권3호
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    • pp.129-133
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    • 2016
  • Theoretical and graphical analysis of pull-in-voltage and figure of merit for a fixed-fixed capacitive Micro Electromechanical Systems (MEMS) switch is presented in this paper. MEMS switch consists of a thin electrode called bridge suspended over a central line and both ends of the bridge are fixed at the ground planes of a coplanar waveguide (CPW) structure. A thin layer of dielectric material is deposited between the bridge and centre conductor to avoid stiction and provide low impedance path between the electrodes. When an actuation voltage is applied between the electrodes, the metal bridge acquires pull in effect as it crosses one third of distance between them. In this study, we describe behavior of pull-in voltage and figure of merit (or capacitance ratio) of capacitive MEMS switch for five different dielectric materials. The effects of dielectric thicknesses are also considered to calculate the values of pull-in-voltage and capacitance ratio. This work shows that a reduced pull-in-voltage with increase in capacitance ratio can be achieved by using dielectric material of high dielectric constant above the central line of CPW.

분산 보상 광섬유의 성능 지수에 따른 40 Gbps 광 펄스의 보상 특성 (Compensation Characteristics of 40 Gbps Optical Pulses Depending on Figure of Merit of Dispersion Compensating Fiber)

  • 이성렬
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2013년도 춘계학술대회
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    • pp.729-731
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    • 2013
  • 축적된 분산(dispersion)과 비선형 효과에 의한 광 신호의 왜곡을 보상하기 위해 사용되는 분산 계수가 -125 ps/nm/km인 분산 보상 광섬유의 성능 지수 (figure of merit)에 따른 40 Gbps의 광 펄스의 보상 특성을 살펴보았다. 보상 특성이 광전송 링크를 구성하는 중계 구간 (fiber span)의 수가 많고 광 펄스의 입사 전력이 클수록 DCF의 성능 지수의 영향을 많이 받는 것을 확인할 수 있었다. 또한 광 펄스의 파장이 광섬유의 영 분산 파장으로부터 많이 벗어날수록 DCF의 성능 지수의 영향을 많이 받는 것을 확인하였다. 그러나 광전송 링크의 비선형 효과가 클수록 효과적인 보상을 위한 DCF의 성능 지수는 낮아져야 한다는 것을 동시에 확인하였다.

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기계적분쇄-혼합공정에 의해 제조된 Bi2Te3 소결체의 열전특성 (Thermoelctric Propretries of Bi2Te3 Fabricated by Mechanical Grinding-Mixing Process)

  • 이근길
    • 한국분말재료학회지
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    • 제7권1호
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    • pp.6-11
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    • 2000
  • Two kinds of Bi2Te3 powders, pure Bi2Te3/2vol.%ZrO2, have been prepared by a mechanical grinding process process. Effect of mixing of the powders on thermoelectric of the sintered body has been investigated by measuring Seebeck Coeffcient, specific electric resistivity and thermal conductivity. With an increase in the weight fraction of the Bi2Te3/2vol.%ZrO2 powder from 0 to 40wt.%. Especially, the figure of merit of the mixedBi2Te3 sintered body increases and thereafter dedreases above 40wt.%. Especially. the figure of merit of the mixed Bi2Te3 sintered bodies with mixing of Bi2Te3/2vol.%ZrO2 powder increased about 1.3time in comparison with the value of the specimen before mixing. Mixing of two kinds of Bi2Te3 powders which have different theramal and electric propertries with each other seemed to be useful methob to increase the figure of merit of Bi2Te3 sintered body.

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Enhancement of Magneto-Optic Figure of Merit of Bi:YIG Films in Blue Wavelengths by La Substitution

  • Lee, Euibok;Jaekyong Cho
    • Journal of Magnetics
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    • 제2권2호
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    • pp.46-49
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    • 1997
  • This paper reports the first success in enhancement of the magneto-optic figure of merit of garnet films in blue wavelengths. The maximum of the absolute value of the Faraday rotation angle observed at about 500 nm for the films with no La substitution shifted toward shorter wavelength as La content increased, that leads the increase of the absolute value of the Faraday rotation angle in the wavelengths shorter than about 480 nm. The optical absorption coefficient at the wavelengths shorter than 500 nm decreased as La content increased. As a result the magneto-optic figure of merit increased in the wavelengths shorter than 470 nm as La content increased and was about two times larger for the film with La content of 0.6 in formular unit compared to that of the film without La substitution. This might be attributed to the shift of the centers of the charge transfer and crystal field transitions by La substitution.

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컴퓨터 시뮬레이션에 의한 TbFeCo 광자기 디스크 두께 최적화 (Thickness Optimization of TbFeCo Disks by Computer Simulation)

  • 김진홍;권혁전;신성철
    • 한국자기학회지
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    • 제4권3호
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    • pp.249-255
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    • 1994
  • 광자기 기록매체의 구조를 유전체층과 반사층을 이용하여 다층화 함으로써 자기광학 효과를 증대할 수 있다는 것은 알려진 사실이다. 본 연구에서는 희토-천이금속 합금박막의 대표적인 재질인 TbFeCo 를 기록층으로 한 다층구조에서 Kerr 회전각, 타원율, 반사도 및 Figure of merit을 Characteristic Matrix 를 사용하여 컴퓨터 프로그램으로 작성하고 이론적 계산을 하였다. Photodiode의 Shot Noise만 고려하였을 때 SNR과 비례관계에 있는 Figure of Merit과 반사도를 기준으로 하여 Bilayer, Trilayer 및 Quadrilayer 구 조에서 최적의 두께조합을 결정하였다.

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완만한 쐐기형 Tail Mass를 갖는 선형배열 수중음향변환기의 FOM (Figure of Merit) 성능특성 개선 (Improved FOM (Figure of Merit) Performance Characteristics of a Linear Array Underwater Acoustic Transducer with a Gradual Wedge-shaped Tail Mass)

  • 이대재
    • 한국수산과학회지
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    • 제54권6호
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    • pp.1036-1044
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    • 2021
  • A linear array acoustic transducer with 12 tonpilz elements mounted independently on a gradual wedge-shaped tail mass was fabricated, tested and analyzed. The compensated transducer, which is modified by including a series inductance of 137 µH in the developed linear array transducer, attained improved figure of merit (FOM) performance characteristics compared with the uncompensated transducer. The four resonant frequency bands were identified from the measured FOM curve. The FOM response patterns over the frequency ranges of 31 to 40 kHz and 50 to 60 kHz were relatively uniform, whereas sharp resonance peaks were observed at around 73 kHz and 84 kHz. These results indicate that the developed linear array transducer can be used as an enhanced broadband transducer of echo sounder, and the operating frequency can be selected for more effective echo surveys in the fishing ground.

Figure of Merit for Deposition Conditions in ITO Films

  • Kim, H.H.;Cho, M.J.;Park, W.J.;Lee, J.G.;Lim, K.J.
    • Transactions on Electrical and Electronic Materials
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    • 제3권2호
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    • pp.6-9
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    • 2002
  • Indium tin oxide (ITO) films were deposited on unheated PET substrates by DC reactive magnetron sputtering of In-Sn (90-10 wt%) metallic alloy target. Electrical and optical properties of as-deposited films were systematically studied by control of the deposition parameters such as working pressure, DC power, and oxygen partial pressure. The figures of merit are important factors that summarize briefly the relationship between electrical and optical properties of transparent conducting films. The formulae of T/R$\_$sh/ and T$\^$10// R$\_$sh/ are expressed as a function of transmittance and sheet resistance. The best values of those figures of merit were approximately 38.6 and 8.95 ($\times$10$\^$-3/Ω$\^$-1/), respectively.